MythTV Software

If hacking on a PVR is more important than using one (and/or you have a system other than the one in the family room to play with!), tracking CVS is the way to go.
Most people are running v0.12, as things KnoppMyth and MiniMyth haven't updated to v0.13 yet...
There's a driver called ivtv that supports the PVR-250
The pcHDTV card comes with a V4L2 driver, it looks like any other dumb capture card for analog NTSC, and provides MPEG streams for ATSC (HDTV) signals.
There's probably no faster/better way to start out than with KnoppMyth ...

If hacking on a PVR is more important than using one (and/or you have a system other than the one in the family room to play with!), tracking CVS is the way to go.